The present disclosure relates to the subject matter contained in Japanese Patent Application No. 2002-271539 filed Sep. 18, 2002, which is incorporated herein by reference in its entirety.
1. Field of the Invention
The present invention relates to a sheet transporting device for transporting a sheet and an electrophotographic type image forming apparatus having the sheet transporting device.
2. Description of the Related Art
As this type of image forming apparatus, an apparatus, in which a sheet transporting device can be attached later to an image forming apparatus body thereby to be constituted in a mode of user""s desire, has been already known (refer to JP-A-2001-2282). The sheet transporting device has a transporting means comprising a pair of rolls for transporting a sheet, and a sheet is fed to the image forming apparatus body by the transporting means of this transporting device. In order to transport a short sheet such as a postcard by this sheet transporting device, it is necessary to shorten a length of a transporting passage between the transporting means. Conventionally, a transporting means for only transporting a sheet is arranged on the image forming apparatus body side, whereby the length of the transporting passage between the transporting means is made shorter than a length of a smallest original document such as a postcard. Further, in consideration of a case where the plural sheet transporting devices are superimposed, another transporting means that receives a sheet from another sheet transporting device and transports it is provided on the sheet transporting device thereby to secure a shorter length of transporting passage than a length of the smallest original document.
However, in the above conventional example, since the transporting means is necessarily provided on the image forming apparatus body or the sheet transporting device, in case where the transporting device is not provided more, this transporting means becomes unemployed parts. This causes useless increase of cost.
An object of the invention is to provide a sheet transporting device and an image forming apparatus in which a short length of a transporting passage is secured, useless parts are reduced, and cost can be reduced.
In order to achieve the object, according to a first aspect of the invention, there is provided a sheet transporting device being attachable to an apparatus body, comprising: a sheet supplying unit body having a joint surface joined to the apparatus body; and a transporting member of which at least a portion protrudes upward from the joint surface of the sheet supplying unit body. According to a second aspect of the invention, there is provided a sheet transporting device being attachable to an apparatus body, comprising: a sheet supplying unit body having a joint surface joined to the apparatus body; a protrusion that protrudes upward from the joint surface of this sheet supplying unit body; and a transporting member disposed on the protrusion, of which at least a portion protrudes from the joint surface of the sheet supplying unit body. Therefore, since the transporting member of the sheet transporting device is protruded upward from the joint surface, a length of a transporting passage between the apparatus body and the sheet transporting device is shortened. Further, since the transporting member is provided on the sheet transporting device, it is not necessary to provide the transporting member on the apparatus body side, so that the transporting member does not become useless in case that the sheet transporting device is not attached.
It is preferable that the above protrusion has a protection cover that covers at least the portion protruded from the sheet supplying unit body, of the transporting member. It is preferable that the protection cover is formed integrally with the sheet supplying unit body. Further, a transporting guide may be formed inside the protection cover thereby to be used as both protection of transporting member and guide of sheet. Further, the transporting member may comprise a pair of rolls. Further, it is preferable that the sheet transporting device is provided with a driving unit that drives the transporting member.
According to a third aspect of the invention, there is provided a sheet transporting device being attachable to an apparatus body, comprising: a first transporting unit including a first sheet supplying unit body having a first joint surface joined to the apparatus body, and a first transporting member of which at least a portion protrudes upward from the first joint surface of the first sheet supplying unit body; and a second transporting unit including a second sheet supplying unit body having a second joint surface joined to the first transporting unit, and a second transporting member of which at least a portion protrudes upward from the second joint surface of the second sheet supplying unit body. In the sheet transporting device thus constituted, plural transporting units are superimposed. In this case, since the second transporting member of the second transporting unit is protruded upward from the joint surface of the first transporting unit, a length of a transporting passage between the transporting units can be shortened. Further, since the second transporting member is provided on the second transporting unit, it is not necessary to provide a transporting member for receiving a sheet from the second transporting unit on the first transporting unit, so that the transporting member is not useless even in case that the second transporting unit is not attached.
Here, it is preferable that a length of a transporting passage between the first transporting member and the second transporting member is the same as or smaller than a length of a smallest transportable sheet. Further, each of the first transporting member and the second transporting member may comprise a pair of rolls, and their pairs of rolls use common parts, whereby cost can be reduced.
According to a fourth aspect of the invention, there is provided an image forming apparatus comprising: an image forming apparatus body; and a sheet transporting device being attachable to the image forming apparatus body, wherein the image forming apparatus body includes an image forming unit and a first transporting member that transports a sheet to the image forming unit, the sheet transporting device includes a sheet supplying unit body having a joint surface joined to the apparatus body, and a second transporting member of which at least a portion protrudes upward from the joint surface of the sheet supplying unit body, and at least the portion of the second transporting member of the sheet transporting device is arranged protrusively into a reception space formed at a lower portion of the image forming apparatus body. Further, according to a fifth aspect of the invention, there is provided an image forming apparatus comprising: an image forming apparatus body; and a sheet transporting device being attachable to the image forming apparatus body, wherein the image forming apparatus body includes an image forming unit, and a first transporting member that transports a sheet to the image forming unit, the sheet transporting device includes a sheet supplying unit body having a joint surface, a protrusion that protrudes upward from the joint surface, and a transporting member disposed on the protrusion, of which at least a portion protrudes from the joint surface of the sheet supplying unit body, and at least the portion of the second transporting member of the sheet transporting device is arranged protrusively into a reception space formed at a lower portion of the image forming apparatus body. Herein, it is preferable that a length of a transporting passage between the first transporting member and the second transporting member is the same as or smaller than a length of a smallest transportable sheet. Further, each of the first transporting member and the second transporting member may comprise a pair of rolls, and their pairs of rolls use common parts, whereby cost can be reduced. Further, it is preferable that a protection cover is provided on the protrusion and fitted into the image forming apparatus body. Since a portion of the sheet transporting device is arranged protrusively into a reception space, the height dimension of the sheet transporting device including the sheet supplying unit body can be suppressed. In other words, the sheet transporting device can contain more sheets compared with a conventional sheet transporting device having the same height dimension.
According to a sixth aspect of the invention, there is provided an image forming apparatus comprising: an image forming apparatus body; and a sheet transporting device being attachable to the image forming apparatus body, the image forming apparatus body includes an image forming unit, and a first transporting member that transports a sheet to the image forming unit, and the sheet transporting device includes a first sheet supplying unit body having a first joint surface joined to the image forming apparatus body, a first transporting unit having a second transporting member of which at least a portion protrudes upward from the first joint surface of the first sheet supplying unit body, a second sheet supplying unit body having a second joint surface joined to the first transporting unit, and a second transporting unit having a third transporting member of which at least a portion protrudes upward from the second joint surface of the second sheet supplying unit body. Herein, it is preferable that a length of a transporting passage between the first transporting member and the second transporting member, and a length of a transporting passage between the second transporting member and the third transporting member are respectively the same as or smaller than a length of a smallest transportable sheet. Further, each of the first transporting member, the second transporting member and the third transporting member may be constituted by a pair of rolls, and their pairs of rolls use common parts, whereby cost can be reduced.
According to a seventh aspect of the invention, there is provided an image forming apparatus to which a sheet transporting device is attachable, the image forming apparatus comprising: an image forming apparatus body having a joint surface jointed to the sheet transporting device, wherein a reception space for receiving a transporting member disposed on the sheet transporting device such that a portion of the transporting member protrudes upward from the joint surface of the image forming apparatus body is formed in the image forming apparatus body.